What role do proteins primarily play in animal tissues?

Proteins serve as major structural materials in animal tissues, providing support and shape to cells and tissues. They form essential components of various structures, such as muscles, tendons, ligaments, and the extracellular matrix, which holds cells together.

Collagen, for example, is a protein that gives strength and structure to connective tissues. Keratin, another structural protein, is key in forming hair, nails, and the outer layer of skin. These proteins contribute not only to the physical integrity of tissues but also to their function, enabling movement and support throughout the body.

While proteins can indeed have roles in energy storage, hormonal regulation, and electrical signaling, these functions do not primarily characterize their main role in animal tissues. Energy storage is mainly handled by carbohydrates and lipids, hormones are often peptides or hormones derived from amino acids, and electrical signaling is primarily managed by ions and certain types of proteins in nerve cells. Thus, the structural function of proteins is foundational to the integrity and organization of animal tissues.